Optimal Integration of Smart Actuators in the Structure of Serial and Parallel Robot Manipulators to Enhance Speed and Tracking Precision Available to Purchase

A method to determine optimal placement of smart (active) materials based actuators in the structure of robot manipulators for the purpose of achieving higher operating speed and tracking precision is developed. The method is based on the evaluation of the transmissibility of the displacement from the integrated smart actuators to the robot manipulator joint and end-effector displacements. By studying the characteristics of the Jacobian of the mapping function between the two displacements for a given position of the robot manipulator, the optimal positioning of the smart actuators that provides maximum effectiveness in eliminating high harmonics of the joint motion or the end-effector motion is determined. In robots with serial and parallel kinematics chains containing non-prismatic joints, due to their associated kinematics nonlinearity, if the joint motions were synthesized with low harmonic trajectories, the end-effector trajectory would contain high harmonics of the joint motions. Alternatively, if the end-effector motion were synthesized with low harmonic motions, due to the inverse kinematics nonlinearity, the actuated joint trajectories would contain a significant high harmonic component. As the result, the operating speed and tracking precision are degraded. By integrating smart materials based actuators in the structure of robot manipulators to provide small amplitude and higher frequency motions, the high harmonic component of the actuated joint and/or the end-effector motions are eliminated. As the result, higher operating speed and tracking precision can be achieved.